Roll stripping mechanism



Oct. l2, 1948. fl.. A. HAWTHORNE 2,450,957

ROLL sTRIPPING MECHANISM v Filed Feb. 17, 1945 2 Sheets-Sheet l ATTORN EY Oct. 12, 1948. i l.. A. HAWTHORNE 2,450,957

nou. smurrmc uncamrsu piled'Feb. 1v, 1945 2 shuts-sheet 2 Tlc' .2..

svi/Mdm@ ATTORNEYK- Patented oei. i2, .1948

Louis A. Hawthorne, Hillside, N. J., assigner to Johns-Manville Corporation, New York, N. Y., a corporation oi' New York Application February 1r, 1945. serial Nia-578,526

l9 Claims. 1

The instant invention relates to appartus for l the manufacture of fibrous sheet products and, more particularly, to improvements in apparatus for stripping the built up sheet from 'an accumulator or build-upV roll of a so'called "Wet machine. Conventionally, orous sheet products suchas asbestos-cement sheets, are formed by depositinga thin film from a wet mixture or furnish of the fiber-cement material onto the endless felt or blanket of the forming machine.

v -A rotatable accumulator roll mounted to have its vsurface in substantial contact with the felt, Dicks up the film from the felt, the roll making the necessary Aturns to build up a plied sheet of the desired thickness. The sheet is then slit and removed from the roll and the operation repeated.

Although various mechanical means have beenv Vheretofore proposed for severing the accumulated sheet and -removing it from the roll, they have not worked out satisfactorily. It is still common practice to station an operator at both ends of the roll, each of whom inserts the point of a knife into a groove extending across the face of the roll and, using the groove as a guideway, slits from the outer edge of the sheet to the middle wherey the cuts meet. This operation frees the sheet and permits it to peel from the roll on continued rotation of the latter, the sheet dropping onto a moving conveyor belt or run-out table. The eiiiciency of operation of the machine is controlled by the skill of the operators in making contact with the groove in the rotating roll during the short interval allowed. Failure of either of them to successfully coordinate their cuts means the loss of the formed sheet.

The mechanical means heretofore proposed vfor the most part comprise swinging doctor blades .or knives. Such expedients have not been satisfactory mainly due to the fact that the sheet is torn rather than cut because of the lapping of` the fibers around the cutting edges. As a result, the percentage of damaged sheets is exceptionally high.

A principal object of the instant invention is the provision of an improved mechanical means for 4effectively stripping the sheet from the accumulator roll Without injury to the sheet. v The device of the invention may be manually operated but, in the preferred embodiment, itsoperation is automatically carried.out under the control of the thickness of the sheet built up on the roll.

vAnother object of the invention is the provision of an apparatus of the type referred to above 2 More particularly, Athe invention resides in the pro'vision. of a stripping member including closely spaced pointed fingers adapted to be moved into operative position to penetrate the sheet and, as y the sheet moves forwardly with the roll, to deect the sheet from the face of the roll.

A still further object of the invention is the provision of means operating in conjunction with, and in timed relationship to, the operation of the stripping means for scraping the surface of the roll after the stripping operation.

My invention will be more fully understood and further-objects and advantages thereof will become apparent when reference is made to the more detailed description of the invention which is to follow and to the accompanying drawings in which:

Fig. 1 is an elevational view of a portion of a wet machine showing the device of the instant invention incorporated therein;

Fig. 2 is a detail view on an enlarged scale illustrating the instant apparatus at one stage of the stripping operation; v

Fig. 3 is a front elevational view on an enlarged scale of the stripper bar of the apparatus of Figs. 1 and 2 in operative position in relation to the accumulator roll; Y

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 3; and

Fig. 5 is a wiring diagram illustrating the con trol circuit forthe stripping device.

Referring now particularly to Fig. 1, a. wet

- machine of the type conventionally employed in which exerts a parting and wedging action on the Shed? as distinguished from a cutting operation.

the Aproduction of fiber-cement sheets and the like, is illustrated in part. The machine includes an endless felt or blanket I0 on which .a thin lap or layer of the fibrous furnish is deposited by suitable rolls (not shown). An accumulator roll I2 is supported for rotation in bearings Il which are mounted for vertical sliding movement on guides i3 of frame structure Il. The roll rests upon the apron. as shown,'whereby upon rotation of the roll, the thin layer of the ber-cement material is transferred from the blanket to the roll andbuilt up thereon in a plurality of convolutions to form a plied vsheet or layer I5 (see Fig. 2) of the desired thickness. For this purpose roll i2 is driven in the direction indicated by the l arrow by any conventional means. Preferably, and as shown, the blanket l0 serves as the driving means. This has the advantage that the surface speed of the built up sheet is maintained 3 conveyor or run-out table I6 roll I2 to receive the sheet.

In accordance with the instant invention, stripis located below ping mechanism, indicated generally at I8, is Y employed to sever the sheet and strip it from the roll when it has reached the predetermined thickness, the stripping mechanism including a scrap- Ving member to remove any residue left on the roll. This mechanism includes a stripper bar 20 of modified triangular cross-section (see Fig. 4)

having pintles 2I rockably supported in bearings l ever, that the fingers may be secured to the bar i in any other suitable manner.

Fingers 26 are chamfered (see Figs. 3 and 4) to provide pointed lower ends 32 and are arranged in the bar to have their chamfered faces lying in substantially a single plane. The fingers are placed at close intervals whereby their chamfered faces provide, in effect, a relatively continuous blade having a serrated or notched lower edge defined by the plurality of points 32.

Located to the rear of the stripper bar, .that is at a point further along in the rotation of roll I2. is the scraper 34 constituting preferably a sharpened blade, adapted to have its scraping edge moved into contact with the stripped roll. Scraper 34 is mounted for rocking movement on supports 36 extending upwardly from brackets 24 on opposite sides of the machine. Suitably, the rockabie -supporting means may comprise pins 38 fixed to ears 4D which extend from the rear side of the blade. The pins are rotatably mounted in bearings in the supports 36.

Stripper bar 20 and scraper 34 may be moved from their inoperative positions to their operative positions for performance of their respective stripping and scraping operations at the proper times by manual manipulation but preferably, and as shown, automatic means are provided for this purpose.

The control means includes a rocker arm 4I, fixed to a projecting end of bar 20 at one side of the machine. The outer end of the arm is pivotly connected to core extension 42 of a push solenoid 44 supported on the horizontal arm or bracket 24, as illustrated. One of the pins 38 supporting the scraper is extended through its bearing in support 36 and the projecting end secured to an arm 46 pivoted to a core extension 48 of a pull solenoid 50 supported on an extension 52 of the horizontal arm or bracket 24. Solenoids 44 and 50 are provided with spring means 54 and 56, respectively, to restore their cores to starting positions after operation.

As previously pointed out, roll I2 is carried in bearings II, mounted for vertical sliding movement on guides I3 to permit the roll to move upwardly as the thickness of the layer on the roll increases. This vertical movement of the roll is made use of to cause operation of the solenoids preferablycomprises an adjustable screw or stud, as shown, whereby the distance through which the roll has to be raised before closing of the contacts, and hence the thickness of the sheet formed on the roll may be varied as desired.

Referring now to Fig. 5, a wiring diagram for the control circuit is illustrated in which the and, hence, movement of the stripper member i several operating elements are shown diagrammatically. In addition to the elements previously described and illustrated in other figures of the drawing, the circuit includes suitable manually controlled switches, illustrated at 66 and 68, and a time delay relay 10. Switch 66, which may be of any conventional type, provides 'a master control whereby the -entire circuit may be disconnected from the power lines 12. The second switch68 is included in a by-pass 69 around limit switch 6I whereby the stripping mechanism may be operated at any time without waiting for the pre-determined thickness of sheet to be built up. That is, when switch 68 is closed the circuit is energized irrespective of the position of contacts 62 and 64 of the limit switch. Time delay relay 'I0 is included in the control of solenoid 50 which operates scraper 34. The time delay relay, which may be of any conventional type, is adjusted to require the current to iiow in the circuit for a predetermined period of time before the solenoid 50 is energized. In the present case the adjustment of the relay is such that operation of the solenoid and, hence, movement of the scraper into contact with the roll will be prevented until the end of the sheet has passed the point of impingement of the scraper blade against the roll, as illustrated in Fig. 2.

In the operation of the apparatus described above, threaded contact 64 of the limit switch 6I is adjusted relatively to the iixed contact a distance equal, or substantially equal, to the thickness of the sheet which is to be built up on the roll I2. Upon rotation of the roll, thin laps of the asbestos-cement or other wet, fibrous furnish are wound thereon, and the roll raised by the accumulated laps until contacts 62 and 64 of limit switch 6I are closed, whereupon current is permitted to flow through the windings of solenoid 44, causing its core and core member extension 42 to move outwardly and swing fingers 26 inwardly against, or substantially against, the surface of roll I2. As the fingers swing toward the roll they penetrate the sheet and, upon continued forward movement of the sheet on the continuously rotating roll, the material of the sheet is pushed aside by the oval contour of the chamfered faces of the pins until the sheet reaches the substantially continuous blade formed by the chamfered facesat their widest parts. At this point severance of the sheet is completed and its freed end is deflected away from the face of the roll to fall by its own weight upon the conveyor or run-out table I6. In the event the sheet end is not sufficiently deiiected by the chamfered ends of the pins and slides up the pins, it will be deflected by the sloping face of bar 20. The sheet is drawn off the roll as rotation of the roll and travel of the conveyor is continued. As the rotation of the roll continues the other end of the sheet is carried with it and finally passes through the bight between the roll and apron or felt I0. When this occurs roll I2 will drop again against Ithe apron, opening contacts 62 and 64 and de-energizing the solenoid which allows spring 54 to pull the solenoid core and extension 42 to the left, as viewed ln Fig. 1. This causes fingers 26 to be swung away from the roll to permit the building up of a new sheet.

v relay which was adjusted, as previously pointed out, to permit a suiiicient time interval to pass before operation of the solenoid to permit the end of the severed sheet on the roll to pass scraper ,34. Uponthe completion of this time interval,

' solenoid 50 becomes energized and scraper 3l is swung intocontact with the roll where it acts to remove any residue of material left thereon. When the circuit is opened by the breaking of 1 contacts 62and 6 4, as previously described, the windings of solenoid 50 will be de-energized'and scraper 34 retracted from contact with the roll under the influence of spring 56.

more, permits the machine to operate at higher speeds than are possible where manual stripping 'operations are employed. Due to the accuracy of the stripping operation, the sheets may be formed to a closer tolerance than heretofore l possible. Also the life of the felts is lengthened because of the straight cuts and more uniform stripping. In addition it has been found that a thinner sheet may be'produced than is possible by the hand stripping method.v That is, under the prior methods it was necessary to relyon the weight of that portion of the sheet freed from the face of the roll by the splitting operation to start the peeling action, such weight, in the case of relatively thin sheets, being insuicient for the purpose. In the operation of the instant apparatus the ngers stayin contact with the face of the roll until sufficient. length of the sheet has been removed from the rol-l that the remainder will be easily peeled-by the pull of the previously removed portion. In this connection it will be understood that by the time the limit switch is opened and the lingers 26 swing into inoperative position, their stripping action is no longer required, the peeling taking place solely by the pull of the deposited sheet.

The contour and character of thev stripping.

` invention as defined by the sub-joined claims.

For example, a hydraulic or pneumatic control system may bev employed yin lieu ofthe electrical system shown. A-iso,'the shape of the fingers may varyv to 4meet particular conditions.

What I claim is:

1. In combination with an accumulator roll adapted for constant rotation, stripping mechanism -for removing at intervals a plied fibrous sheet built up thereon, said mechanism comprising-a stripper bar extending' lengthwise of said roll, a plurality of closely spaced pointed fingers carried thereby, and means controlled by 6 the thickness of the sheet on said roll to cause said fingers to move from a position away from said roll to a position substantially against said roll with said fingers pointing substantially opposite to the direction of rotation of the roll whereby said fingers penetrate said sheet and, upon continued rotation of the roll, the sheet moves along said fingers and is parted thereby and removed from said roll.

2. In combination with a rotatable accumulator roll adapted for constant rotation, stripping mechanism for removing at intervals a plied brous sheetvbuilt up thereon, said mechanism comprising a stripper bar extending lengthwise oi' the roll and adjacent thereto, a plurality of closely spaced rod-like fingers forming a relatively continuous blade carried by said bar, s aid fingers having chamfered ends with the points' thereof toward said'roll, and means controlled by the thickness of said sheet to actuate said bar to cause said fingers to move from a position away from said roll to a position substantially against said roll with said fingers pointing substantially opposite to the direction of rotation of the roll whereby said fingers penetrate said sheet and, upon continued rotation of the roll, the sheet moves alongsaid fingers and is parted thereby and removed from said roll.

3. In combination with a rotatable accumulator roll, stripping mechanism for removing a plied brous sheet built up thereon, said mechanism comprising a stripper member extending lengthwise of the roll, a scraperpositioned above said stripper member, and means to cause said -stripper member to move into stripping relationship to said roll for severing said sheet and removing it therefrom and for causing said scraper to move against the stripped rol-l in timed relationship to the movement of said stripper. member, said last-named means including electrically controlled actuating devices for said stripper member and scraper respectively, mechanism operatively connecting 'said stripper member and scraper with their respective actuating devicesl a switch for controlling the operation of said actuating devices, said switch including a fixed contact and a movable contact carried by the roll and arranged to he moved into position to engage said fixed contact upon the building up of a sheet on said roll, and means operatively connected with said switch and actuating device ,for said scraper to delay the operation of such actuating device until the severed end of the sheet passes the scraper.-

4. In combination with a rotatable accumulator roll having means for rotating it in a-given direction, stripping mechanism for removing a vfibrous sheet built up on the roll, said mechaand penetrating said sheet whereby rotation Aof the roll causes said sheet to move alongv said :fingers and to b'e parted thereby and removed from the roll.

5.In combination with a rotatable accumulator roll having means for rotating the roll in a given direction, stripping mechanism for remov- Y ing a fibrous sheet built up on the" roll, said stripping mechanism comprising a stripper bar extending lengthwise of the roll, a plurality 'of closely spaced fingers forming a relatively continuous blade on said bar. said fingers including pointed ends, and means mounting said bar for rotation to swing said fingers toward said roll and into stripping position with the ngers pointing substantially opposite to the given di-v rection of rotation of the roll and penetrating said sheet whereby rotation of the roll causes said sheet to move along said ngers and to be parted thereby and be removed from said roll.

6. In combination with a rotatable accumulator roll having means for rotating it in a given direction, stripping mechanism for removing a iibrous sheet built up on the roll, said mechanism comprising a stripper bar extending lengthwise oi.' the roll, a plurality of closely spaced fingers forming a relatively continuous blade carried by said bar, said fingers including pointed ends. means mounting said bar i'or rotation to swing said lingers toward said roll into stripping position with the fingers pointing substantially opposite to the said direction of rotation of the roll and penetrating said sheet, and means controlled by the thickness of the sheet to rotate said bar into saidstripping position.

'7. A stripping mechanism for a rotatable accumulator roll having means for rotating it in a given direction, said mechanism comprising a stripper bar extending lengthwise of the roll, a plurality of closely spaced rod-like ngers forming a relatively continuous blade carried by said bar, said fingers having chamfered ends with their points toward said roll, means mounting said bar for rotation to swing said ngers toward said roll into stripping position with the ngers pointing substantially opposite to the direction of rotation of the roll, and means for rotating said bar to swing said fingers into said stripping position.

8. In combination with a rotatable accumulator roll, a stripper bar extending lengthwise of the roll. a plurality of closely spaced ngers carried by said bar, means mounting said bar lor rotation to swing said lingers toward said roll into stripping position with the ilngers pointing substantially opposite to the direction of rotation of the roll, mea'ns to rotate said bar into stripping position, a scraper blade supported above said stripper bar for movement toward and away from said roll, and means to move said scraper blade against the rou in timed relationshipte the movement of said fingers into stripping position.

9. In combination with a rotatable accumulator roll, a stripper bar extending lengthwise of the roll, a plurality of closely spaced fingers carried by said bar, means for mounting said bar for rotation to swing said fingers toward said roll into stripping position with the ilngers pointing substantially opposite to said direction of rotation oi the roll, a. scraper supported above said stripper for movement-toward and away from said roll. means controlled by the thickness ot the sheet built up on the roll to rotate said stripper bar and move said lingers into stripping position, and means to cause said scraper to move against the rollin timed relationship to the movement of said fingers.

LOUIS A. HAWTHORNE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 336,330 Lawrence Feb. 16, 1886 628,186 Rutschman July 4, 1899 986,976 Hanson Mar. 14, 1911 1,315,227 Libert Sept. 9, 1919 2,100,284 KreichbaumA Nov. 23, 1937 2,355,006 Millspaugh Aug. 1, 1944 2,396,104 Kingman Mar. 5, 1946 

